Trimming machine



Oct. 17, 1950 c, sHlPPY ETAL 2,526,153

I TRIWING MACHINE Filed June 21, 1947 6 Sheets-Sheet 1 Zhwentors Qct.17; 1950 L. c. SHIPPY El'AL 2,526,153

immune mammal 6 Sheets-Sheet 2 Filed June 21, 1947 3nuentors 6Sheets-Sheet 'Jmaentors 7% 11W 'J. W9

L. C. SHIPPY EFAL TRIMMING MACHINE Oct. 17, 1950.

Filed June 21, 1947 1;. c. SHIPPY ETAL TRIMMING MACHINE 6 Sheets-Sheet 4Filed Jut't 21, 1947 Zmventors 0 $419375 Oct. 17, 1950 L. c. SHIPPY rm.2,526,153

'ramumc momma Filed June 21, 1947 6 SheeiS-Shet 5 r-IN Oct. 17, 1950 L.c. SHIPPY EIAL 2,526,163

' TRIMMING MACHINE. Filed June 21, 1947 v s Sheets-Sheet e SunentorsPatented Oct. 17, 1950 TRIMMING MACHINE pen 0. Shippy and Elwood n. Sy,Lockport,'N. Y.,

ass'ignors to Y General Motors Corporation,

Detroit, Mich, a corporation of Delaware Application June 21, 1947,Serial Nor 756,198

This invention relates to an improved machine for trimming or cuttingthe draw flange from a shell drawn from sheet metal as a ,finishingoperation to provide a straight sided wall having a clean cut.- I

A preferred. embodiment of the improved machine consists essentially ina pair of cutting dies, one to be projected into fixed position insidethe shell and the other to surround the shell and to be laterallyshiftable for cooperation-with the cutting edge of the inner'stationarypositioned die to shear through the shell wall from the outside to theinside below the draw flange and to be actuated by a series ofcontractible-expansible power devices controlled intimed sequence toimpart to the outer die an oscillating movement starting at a point'andcontinuing around the shell perimeter to the starting point, with anangular shear action throu hout its entire circuit. i V

In general it may be said that the oscillation of the outer shear ringis accomplished by means of spaced apart hydraulic piston cylindermotors with at least one providing reciprocation in a directionsubstantially at right angles to the general direction of reciprocationproduced by the others and all being swivelly mounted for a slightswinging action to com ensate for reIati' e projection and retraction ofthe several pistons in a predetermined cycle. By properly cycling therelative projection and retraction of the pistons the shear n is hiftedfore and aft and sidewise through an oscillatory travel pattern whichbrings together the cutting edges in angular relation at a givenstarting point and the continuous cutting all the way around so as toprogressively shear through the shell wall. 1

In the accompanying drawings ill strating the preferred embodimentreferred to Figure 1 is a front elevation of the machine assembly partlyin section and-with the dies in open relation; Figure 2 is an enlargedplan view of the machine bed plate looking in the direction of thearrows on line 22 of Figure l and showing the outer shear ring incentered relation to the inneridie, which latter anism' and isillustrative of'the several cams by which the operation of the'machineis cycled; Figures 9 to 14, inclusive, are diagrammatic views showingseveral relative positions of theinnerand V outer shearing steels intherange of oscillation of Claims. (01. 164-56) the outer die ring andFigure 15 is a diagram of the -hydraulic control circuit.

Referring to the drawings, the bed plate I is supported above the doorupon suitable standards which also house the hydraulic operatingmechanism, the manual controls which are mounted on the front face ofthe machine within convenient reach of the operator, as seen inFigure 1. Projecting upwardly above the bed plate are a series of posts2-2 for slidably guiding a vertically reciprocal ram 3, whose piston rod4 has its piston 5 enclosed within a cylinder 6 supported by a cross bar1 carried at the tops of the posts 2 -2. Fluid pressure directed to thetop of the cylinder 6 will lower the ram for closing the dies over thework positioned therein and pressure fluid delivered to the bottom ofthe cylinder 6 will raise the ram upon completion of the die shearingoperation.

Adjustable stops to limit the extent of downwardram movement areprovided by means of dependent posts 88, carried by the cross bar 1' andterminating in enlarged heads'for abutment by adjustable sleeves 9, asbest seen in Figure 7. Unison adjustment of the sleeves for both stoprods 88 is afforded by a single hand crank H2 mounted on a worm shaft Hand which has a chain drive I2 with a companion worm shaft I3 and eachworm is geared to a wheel [4 keyed to a nut It having threadedengagement with the stop sleeve 9 slidably keyed on the post 8. Thus byturning the crank it the stop sleeves may be raised and lowered inunison to change the lower limit of ram travel and thereby set up themachine :for proper alignment of the die cutting edges.

At the lower limit of ram closing movement the inner die is held infixed position during the die cutting operation. This inner die, whichis removably secured by screw studs 15 to the bottom of the ram is shownas consisting of a holder ll to which is fixed a plate-like cuttingsteel it. Its cutting edge is formed by its lower corner around the foursides in the case of a die for a blank having :four rectangular walls,as is true of the drawn shell it as illustrated. The companion cuttingedge is afforded by the upper interior corner of a cutting steel, ring29 secured to a holder 2i which is detachably held by screw studs 22 toa, die plate 23 slidablymounted on the top surface of the bed plate I.shifter plate 23 includesas an assembly therewith a shouldered retainerring 2 5 slidably engaging the widersuriace of an inwardly extendingshoulder on the bed plate l bounding the die opening therein. It alsoincludes a U-sha-ped strap 25 whose arms are welded or otherwise securedto the retainer ring 2d and which mounts a work stripper and clampingelement. bolts 26 secure to the strap 25 a strap 2? for slid Spacer Iably locating a pair of guide bolts 28 on a bar 29, which is depressibleagainst the elastic force of coil springs 39 surrounding the bolts 28and engaged at opposite ends with the bars 21 and 29. A central buttonor contact member on the stripper bar 29 cooperates with a central post3| shiftably carried by the ram to engage and clamp the bottom of theshell l9 against the spring pressed stripper when the ram is closed. Thepost 3i is mounted on a slider or filler plate 32 which rests againstthe bottom of the die steel 18 and is flexibly suspended by means of apair of swinging bolts 33. Each bolt has a semispherical head seated ina socket in the plate 32 and a coil spring surrounding the bolt andretained by the end nut presses against the semispherical washer seatedin a socket in the die holder I? so that the spring maintains the platein snug sliding contact with the die and tends automatically to centerthe filler plate 32 while accommodating its sidewise shifting movementsby the tilting of the bolts 33 when the outer ring is shifted during theshearing operation, as seen in Figure 4.

The shearing operation occurs when the outer ring and with it the shellor work is shifted laterally in relation to the inner die [8. To shearthrough the four side walls of the shell the outer die must be shiftedfrom side to side in both directions and forward and backward and for anangular shear out the ring needs to be cooked relative to the fixedinner die as an incident to its travel. This conveniently isaccomplished by the use of three spaced apart power motors arranged asseen in Figure 2, with one at the side and two of the motors at the rearof the machine toward the right and left-hand ends of the shiftablering. Each motor has its plunger secured to the ring by a pivot pin, asindicated by the numeral 35, and has its opposite end swiveled by a pin37 mounted on an adjustable lever 38 fulcrumed at one end on the bedplate I and having its opposite end located between a pair of adjustableplungers, at least one of which is in the nature of a set screw mountedin a machine bracket 39 whereby the machine can be set up so that thecutting ring is properly centered with reference to the inner die steel[8. The projection and retraction of the plungers relative to each otherwill control the pattern followed by the die ring in shearing off thedraw flange.

structurally the several plungers are identical and each includes theswiveled cylinder 48 and the plunger 4|. The interior of each cylinderhas shouldered portions receiving a large piston 42 and a small piston43, the latter of which is fixed to the plunger 4|. As seen in Figure 3,the pistons are centered in the step cylinder bore with the largerpiston 42 seated against'the intermediate shoulder and in turn seatingthe inner end of the smaller piston 43. Suitable spacer formationsafford clearance between abutting face areas of the two pistons and theintervening space communicates with a lateral port 44 in the pistonwall. Similar ports 45 and 46 communicate, respectively, with the innerside of the larger piston and the outer side of the smaller piston.Restricted ports 4''! and 48 communicate the central port 44 with therespective end ports 45 and 46. Thus if the central port 44 is vented oropened to a drain while pressure fluid is delivered to both of the ports45 and 4B the pistons will be held in the centered relation shown. Toproject the plunger outwardly the re- 4 lief or drain from the port 44may be closed whereupon pressure will build up on the inner face of thesmall pistons 43 and since its effective surface area is greater thanthat presented to the pressure on the outer face of the piston anoutward movement of the plunger will occur. For retracting the plungerto centered position the port 44 is again open to drain and for afurther retraction of the plunger to its innermost limit pressure fluidcan be cut off from the port 45, which is then vented through theconnecting passage 41 so that pressure on the outer side of the smallerpiston moves the larger piston 42 to its inner limit. Restoration tocentered position will occur when pressure fluid is again introducedinto the port 45,

To initiate the cut starting at the forward left-hand corner at the sidewall of the shell or that which as seen in Figure 2 is toward thelefthand bottom of the view, the plunger in the single side cylinder isprojected outwardly and at the same time the plunger in the left-handback cylinder is also projected outwardly slightly so that the ring istilted in relation to the fixed inner die and its edge adjacent theforward left-hand side of the die is brought into cutting relation witha corresponding point at the cutting edge of the fixed die. The movementcarries with it the blank or shell and the backing or filler plate 32into the relation illustrated in Figure 4. Continued outward projectionof the plunger in the side cylinder will continue the shearing actionthrough the right-hand side wall of the shell toward the rear of themachine until the dies assume the relative position illustrated inFigure 9. Further outward projection of the plunger in the left-handrear cylinder will start the cutting knife shearing through the backwall with a continuous travel toward the right until a midpoint in thelength of the wall is reached when the plunger is fully projected. Therelation of the parts will be that generally illustrated in Figure 10.Coincidentally with the final outward projection of the left-hand rearplunger will be the outward projection of the right-hand rear plunger tocontinue the cutting through the back wall to completion when therelation of the parts will be that illustrated in Figure 11, wherein allthe plungers are at their outer limit. To sheer forwardly through theright-hand shell wall the pistons in the right-hand rear cylinder andthe single side cylinder are both retracted inwardly in a proper ratioof speed and at the completion of the cut the parts will be in therelative position shown in Figure 12. Thereafter the front wall will besheared toward the left with a continuation of the inward retraction ofthe righthand rear plunger until a mid-point is reached, as seen inFigure 13, whereupon the left-hand rear plunger will be started inwardlyto complete the shearing operation when the parts will assume therelation illustrated in Figure 14. All plungers may then simultaneouslybe returned to centered position for returning the dies to the centeredrelation shown in Figure 2.

Automatic operation of the machine through a given cycle can becontrolled by suitable hydraulic circuit, such as diagrammaticallyrepresented in Figure 15. As here seen the outer ends of each of thethree cylinders have their ports 46 joined by branches of a deliverymanifold 50 to which pressure fluid is supplied by a motor driven pump5| from a sump or supply reservoir 52. Manually set metering valves 53in each branch insure proper ditribution of the fluid between theseveral cylinders. Each central drain p01 M is connected to a drainmanifold 54 leading back to the sump 52 under control of individualslide valves 55-5E. Properly contoured cams 55a, 55b and 550 on a commonshaft 56 time the operation of the respective slide valves 55. Deliveryof pressure to the end ports I 45 of the several cylinders from thepressure manifold is under control of separate valves 5?, one for eachcylinder, and the operation of these are timed by the respective cams5M, 5% and tile on the shaft 56. Another timing cam 53 on the shaft 56controls the slide valve 59 which communicates with the deliverymanifold 58 to one or the other of the delivery lines 60 and ti leadingto the opposite ends of the ram operating cylinder 6. When the valve 59is operated to direct pressure fluid selectively through one of thelines 68 or til the other line simultaneously is connected to the drainmanifold 54. Both of the pressure delivery lines 63 and 6! are alsoconnected to a pressure relief valveBZ for bypassing excess liquid backto the drain manifold 54. As a further safety precaution against excesspressure build-up a limit valve 63 is provided in the line 6% to beopened by engagement of the ram as it reaches its upper limit of move-'ment. For machine set-up purposes a normally closed control valve 54 isprovided to connect the opposite sides of the plunger 6. For rotatingthe cam control shaft 56 through one revolution a fluid pressure motor65 having a manuall con trolled pressure control valve 85 is provided toreceive pressure fluid from a pump 61, also connected with the supplytank 52. A pressure relief valve 68 joins the pressure delivery linefrom the pump 6? to the drain manifold 54 and a similar pressure reliefvalve 69 is provided for the pressure fluid manifold 50 associated withthe pump 5!. A valve 10 controls communication from the pump 61 to theoperating motor 65 and this valve is under manual control of a startingbutton H and a stop button 12 as Well as under automatic control of acam 13 on the shaft 56. The manual stop button normally is provided forsafety purposes and ordinaril the cycling of the machine is begun whenthe starting button is depressed to feed pressure fluid to the operatingmotor 65.

Assuming that the dies are open and a blank has been inserted in themachine the operator, by depressing the starter button, will cause themachine automatically to go through its cycle beginning with thedepression of the ram 3 to close the dies and thereupon through theseveral cams control the proiection and retraction of the several dieshifting cylinders in prede ermined sequence after which the dies areopened and the control cam 13 cuts off further pressure fluid flow tothe motor 65. When flow to the motor 65 is diverted it is directed to afilter M and a heat exchanger !5 before returning to the sum in order toavoid excessive liquid temperature and the circulation of sledge anddirt. V

' We claim:

1. In a shearing machine, a reciprocatory ram having a cutting diemovable to open position for insertion and removal of a workpiece intothe machine and movable to closed stationary position inside theperipheral wall of a work piece insered in the machine, a shiftablecarrier for the workpiece shiftablein all directions in a single eralwallof the workpiece for cooperation with the fixedly located die, apair of travel guides for said ram having stops to define the limit ofram closing travel, adjustable bearing sleeves on the ram for terminalabutment with said limit stops and hand crank operating mechanismarranged to adjust said sleeves in unison for the closed posi tionsetting of said cutting die in proper operative relation with the sheadie ring.

2. In a shearing machine, a cutting ring for cooperation with a cuttingdie surrounded thereby, a support shiftabl mounting said ring, means toimpart an oscillatory path to said ring for progressive annular shearingtravel aroun the cutting die, including a series of fluid pressuremotors joined to the ring at spaced points, a source of motor operatingfluid pressure, valving controlle ing pressure fluid circulation to saidmotors and timing mechanism for cycling the control valving for pressurefluid delivery according to a'predetermined sequence.

3. For shearing through an annular wall of a workpiece, cooperating maleand female dies to receive the wall therebetween, a plurality of poweroperated plungers pivotally joined at spaced apart points to one of thedies for moving the same in various directions in a single plane, meanspivotally mounting each plunger for swinging travel in said plane, eachrelative to the other and cycling mechanism for applying operating powerto the respective plungers in predetermined successive relation andthereby oscillate said movable die in angular shearing relation with theother die in continuous circuit through the annular Wall of theworkpiece.

4. In combination, a air of cooperating shear dies, a series of powerdevices hinged in spaced apart relation to one of the dies, swiveledmounts for said devices to enable their relative oscillation underdiiferential operation thereof, and operating cycle control meansgoverning power response of said devices in given successive action forrelative swinging of the dies.

5. In a device for effecting an angular cut in a continuous circularpath through an annular wall, an annular shear die to surround theannular wall to be sheared, a fixed support, a set of three poweroperated expansible-contractible devices, each comprising a plungermember and a casing member, means hingedly connecting one member of eachdevice to the fixed support and the other member of each device to theshear dies in an arrangement wherein the expansion and contraction oftwo of t e devices is directed angularly to that of the third device,and means to supply power to said devices in timed sequence and therebyoscillate the die through six consecutive shearing strokes, eachsuccessive stroke shearing through the wall starting from the end of thepreceding stroke shear and completing the shearing operation in onecontinuous sweeping circuit.

. LEO C. SHIPPY.

ELWOQD H. SY.

, REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1.717,612 McNeil June 18, 19292,363.40? Foster Nov. 1, 1944 2,413,980

Liss et a1 Jan. 7, 1947

